Method of eliminating knocking in internal combustion engines



Dec. 10, 1935. 1. B. KIMBALL 2,023,892

METHOD OF ELIMINATING' KNOCKING IN INTERNAL COMBUSTION ENGINES OriginalFiled Dec. 2, 1932 m & m v 5 m 0 N P E n m A o 0 4 m T Patented Dec. 10,1935 UNITED STATES METHOD OF ELIMINATING KNOCKING 1N INTERNAL COMBUSTIONENGINES Leo B. Kimball, New Haven, Conn., assignor to Fuel DevelopmentCorporation, a corporation of Delaware Original application December 2,1932, Serial No.

Divided and this application January 18, 1934, Serial No. 707,081

2 Claims.

This invention relates to certain improvements to be applied to internalcombustion engines of the explosive type, in which knocking is oftenproduced for example, when an automobile is 5 traveling at high speed ortraveling up steep grades and under other conditions which require thedevelopment of considerable power by the engine.

This application is a division of my prior application, Serial No.645,337, filed December 2, 1932. This invention relates particularly tothe method of controlling the points of occurrence of the ignition sparkor timing as determined by the angular positions of the contact pointsof the distributor forming a part of the electrical system of anautomobile engine.

It has been found that the timing of the spark that is, whether theoccurrence of the ignition spark is retarded or advancedhas a veryappreciable eifect upon detonation or knocking in an automobile engine.

In the present day automobile construction, the spark control, whicheffects the advance or retardation of the spark, is usually producedautomatically by governors installed when the engine is assembled. Theusual spark controls produce an advance of the points of ignition of thecharge in relation to the speed of the engine. It approximates theoptimum position for maximum output and economy under best conditions ifand when the throttle valve is wide open. This has also beenaccomplished manually. Such means are not sufiicient to produceanti-knock or antidetonating conditions in the engine at all times,

because of the fact that differences in atmospheric pressure,temperature and moisture content, in fuels and in engine conditionsconstantly occur. These all have very marked efiect upon the amount ofknocking or detonation produced by the ignition of the charge in thecylinders.

It is a main feature of this part of my invention to provide a procedurewhereby the point of production of the ignition spark may be determinedin accordance with the power demanded of the engine, and determined inaccordance with the operation of the accelerator or throttle valvecontrolling devices. This may be independent of or in combination withthe action of automatic sparkcontrol above referred to. For thispurpose, I have provided connections with the throttle valve or powercontrol devices of the engine as indicated in my aforesaid application,so that the point of ignition is adjusted in relation to the powerdemanded of the engine, to eliminate knocking, regardless of the speed,when under such abnormal conditions as may exist.

For a detailed description of one form of my invention for carrying outthe method described herein and which is at present deemed preferable, 5reference may be had to the following specification and to theaccompanying drawing forming a part thereof, in which:

Fig. 1 is a side view in elevation shown partly in section, of anautomobile engine having the 10 improved apparatus applied thereto;

Fig. 2 is a plan view of the top of a usual form of distributor for asix-cylinder engine;

Fig. 3 is aside elevation, partly in section, of

the device constituting part of my invention for 15 varying andcontrolling the distributor so that the spark may be retarded oradvanced, the positions shown being for maximum retardation of the sparkwhen the throttle valve is opened.

Fig. 3 is a view similar to Fig. 3 but showing 20 the inclined cams inposition for no retardation of the spark or points of ignition;

Fig. 4 is a vertical sectional view of the device illustrated in Fig. 3but taken at a right angle thereto; 25

Fig. 5 shows a side elevation of a portion of the manual control thatmay be attached to the' steering post of an automobile so that the sparkor ignition control may be easily operated by the driver; and I 30 Fig.6 is a plan view of the upper end of the controlling device on thesteering post, and indicates the means for determining the amount ofmanual displacement of the spark retarding or advancing device. 35

Fig. 7 is a plan view of the means for connecting applicants improvedspark control with the throttle valve. v

Referring to the drawing, the numeral I indicates the casting or blockcontaining the cylinof the engine by the foot of the driver. This isusually provided in addition tothe manual control (not shown) of thethrottle valve from the steering post as is well understood in the art.The support 1'- for the button 1 extends to and engages a crank arm 8which is fixed to a transverse shaft 9 (Fig. 7). The shaft 9 also hasfixedthereon a crank arm 9 provided with the usual rod 9 which connectswith any preferred form of throttle valve (not shown). A third crank arm8 is fixed to the shaft 9, as shown in Fig. 7, and pivoted thereon isone end of a rod I 0. The latter is also pivoted at its forward end to acrank arm II which is fixed adjustably upon one end of a sleeve l2 thatis within the casing l3 containing the cams, for determining theposition of the distributor which controls the retardation or advance ofthe spark.

The lower end of the sleeve I2 is provided with a flanged portion l4,and projecting from the lower surface thereof are diametrically disposedconcentric arcuate projections l5. Said projections each have inclinedsurfaces It at diametrically opposite points. A shaft ll passes throughthe sleeve I2, and its 'upper end enters a cap I8 which is pinned orotherwise fastened to said shaft, as indicated at I 9. To the lower endof the shaft I! there is fixed a flanged member 20, having arcuateprojections l5 similar to the projections l 5 on the flange l4 abovementioned, and having inclined surfaces 2| corresponding in angle to theinclined surfaces IS on the flanged member II, as indicated in Fig. 3.

The cap l8 is'provided with an arm 22 to the outer'end of which a rod 23is pivoted. The

opposite end of said rod 23 is pivotally connected with a bell cranklever 24, which has a fulcrum 25 and a projecting arm 26. The outer endof the arm 26 is pivotally connected with a rod 21 extending upwardalong the surface of the steering post 6. The upper end of said rod 21is provided with teeth in the form of a gearrack 23 and said rackengages a pinion 29. Said pinion is carried within a casing 39 attachedto the steering post 3-, as indicated in Figs. 5 and 6. The gear 29 isfixed to a rotatable stud 3|, the outer end of which is provided with acap or thumb nut 32. The surface of said cap or thumb nut may beprovided with a series of transverse lines or marks forming a scale 33,or other means may be used to.locate its angular displacement. When thescale is used it may cooperate with a pointer 34 projecting from a fixedpart of the casing 30. I

The distributor 3 is provided with a laterally projecting arm 33. Saidarm carries a screw or bolt 36 which engages a flexible member or wire31 to hold it pivotally in position on said arm.

The numeral 38 indicates a suitable bracket attached to a fixed part ofthe engine block, and the upper end thereof is provided with a tubularclamp 39 which receives and fixes one end of a flexible tube 40. Betweenthe clamp 39 and a flange or washer ,adjacent the screw 36, there isplaced a helical compression spring 42. It will thus be appreciated thatthe spring 42 tends to force the arm 35 and the screw or bolt 36 towardthe right. The flexible wire 31 extends through the tube 40, the lowerend of the latter being also retained in position by a bracket 43similar to the bracket 38. The said flexible wire projects from saidtube 40, as indicated in Fig. 3.

and is fixed within the top of the cap I 8 by the set-screw 44, asindicated in Fig. 4.

It will now be seen that'the angular position of the flange 20 withinthe casing l3 and'the position of the inclined surfaces 2| carriedthereon will be determined by the position of the thumb nut 32 on thesteering post 6, since the said thumb nut is connected with the crankarm 22, by the rod 21, bell crank lever 24, with the rod 23, whichdetermines the position of the arm 22, the shaft l1, and the flange 20.

The throttle valve control or accelerator button 1 being carried on thecrank-arm 8, which oscillates the rod connected with the crank 5 arm II,the sleeve l2 will be oscillated thereby so that the flange l4 and thearcuate projections I 5 will be oscillated angularly and be caused toassume various positions.

As willbe understood by one skilled in the 10 setting of timingmechanism for internal combustion engines such as automobile engines,the advance of the spark contact by the distributor is so arranged thatthe contact is made at a point several degrees, during the motion of thecrank arm of the engine crank shaft, in advance of its reaching the topdead center position or point of maximum compression. This is for thepurpose of allowing the lag in the flame propagation, etc., to completethe combustion of the compressed gases so that the maximum pressure ofcombustion will occur at or immediately after the point of greatestcompression or top dead center position. The usual automatic sparkcontrol device connected with the timing mechanism is often so arrangedthat the spark is advanced to a considerable extent as the speed of theengine increases. In fact, in some makes of automobile engines, thisadvance per cylinder as to the ignition point is made at an angle ashigh as 50 or 60 degrees prior to the position of the crank arm andpiston reaching their top dead center or position of maximumcompression. This isbecause of the fact that, although the speed of theengine increases, the rate of combustion and flame propagation withinthe engine is nearly constant and therefore does not correspondinglyincrease. Hence, in order to bring about complete combustion at theright time, the spark must be antomatically advanced. This advance inthe spark often, in some types of engines and particularly when a lowgrade of gasoline is used or there has been considerable c'arbondeposit, produces knocking or detonation.

It is, therefore, one of the objects of this in- 45 vention to eliminatethe disadvantages of knocking, without changing the fuel economy overthose ranges or sections of the throttle valve opening during whichdetonation does not occur. This result may be produced without aflectingthe action of the automatic spark control that acts according to thespeed of the engine, when the latter is employed.

As shown in Fig. 3, the arcuate projections forming inclined camscarried by the flanges ll and 20, respectively, are in such positionsthat the inclined portions thereof are at the limit of their actions andthe inclined surfaces of the said arcuate projections are just out ofcontact.

Now, assuming that the cams are in the relative positions indicated inFig. 3* and that the thumb nut 01'' head 32 has not been moved, and thatthe automobile is being run at a moderate speed on a highway, and someknocking takes place in the engine, the thumb nut 32 may then be rotatedin 66 a clockwise direction (Figs. 1 and 5) so that the rack 28 will bemoved downward to pull the rod 23 toward the right. This will swing thearm 22 toward the right (Fig. 3) and rotate the flange 20 and thearcuate projections I! in a corre- 70 sponding direction to cause theinclined surfaces,

2 I, on the flange 20 to contact with and then slide downward on thecorresponding inclined surface I6 carried by the flange l4, therebycausing said flange 20, the shaft II, the cap I3, and the flexible wire31, to move downward. This will cause the arm 35 in Fig. 2 to be forcedtoward the left, thereby slightly rotating the contact points of thedistributor in the same direction. This has the effect of retarding thespark so that the ignition of the compressed fuel is somewhat delayed,to prevent the complete combustion taking place until after the crank onthe crank shaft has passed its top dead center position or the point ofmaximum compression over that range of power variations at whichknocking occurs.

It will thus be seen that the operation of the thumb nut or head 32 hasretarded the spark over a predetermined range of power output, andtherefore, if under prior conditions the engine has been knocking, theknocking will be eliminated.

It is often necessary to supply more fuel to the engine, particularlywhen an automobile is ascending comparatively steep grades or hills.This may cause the knocking to develop again in the engine on account ofthe increased efiort required, and the greater quantity of fuel used.Since the flange l6 and the arcuate projections I5, carried thereby, areconnected with the throttle valve control or accelerator button I, saidflange and the projections thereon will be'moved when the accelerator isdepressed to produce more power.

Thus it will be seen, from an inspection of Figs. 1 and 3 that when theaccelerator button I is depressed, the rod Ill and the crank arm II willbe moved toward the left, which will cause the arcuate projections l5carried on the flange l4 to be moved in the same direction. This, aftera certain preliminary movement, will again cause the inclined surfacesI6 and 2! of the arcuate projections I5 and I5, respectively, to slideupon each other and draw downward the shaft [1 by a further amount whichincreases as the throttle valve is opened. In a similar manner as abovedescribed, this will cause the cap l8 and the shaft I! to move downwarda correspondingly greater amount. This motion of the wire 31 will thenmove the arm 35 further toward the left, thus moving the spark contactpoints of the distributor toward the left and still further retardingthe point of ignition until the maximum point of retardation is reachedas shown in Fig. 3. The reverse motions of the parts above referred towill serve to advance the spark timing.

The movement of the accelerator button, without any further attention ofthe operator, will consequently and automatically preventknocking of theengine even under heavy loads when an automobile is going uphill ortraveling at high speed, and at other loads'on the engine will preventknocking if it tends to occur, due to bad engine conditions or poorfuel.

The method above described, as well as the apparatus for carrying outthe same, enables the operator of an automobile or other devicerequiring power and in which an internal combustion engine is used, tocause the engine to function with a maximum advance of the timing orspark ignition consistent with the characteristics of the fuel and thecondition of the engine. This means that the engine can always beoperated at its maximum efflciency under existing conditions without thepresence of detonation or knocking.

It will thus be apparent that the knock-preventing mechanism dependsupon two factors:

First, the setting of the distributor points in such angular positionsthat knocking is eliminated at substantially all speeds, and second, anadditional control or timing of the istributor points when greateroutput is demanded, and the throttle valve opening is increased.

I do not wish to be understood as being limited to the use of thevarious details of procedure described in connection with thisembodiment of my invention, since the present application relates to theacts and operations employed in the necessary setting of the sparkcontrol devices to eliminate knocking at high speeds or when greaterpower is required of the engine, and combining therewith the setting ofthe control of the distributor to fix the range over which the firstsettings shall take place.

What I claim and desire to protect Patent, is:

1. The method of controlling the advance and retardation of the sparkignition in internal combustion engines, which comprises, varying thetimes of ignition concurrently with various degrees of throttle valveopening, and in addition thereto, manually producing certain amounts ofretardations of the first mentioned times of ignition over limitedsections of the range of throttle valve openings, to eliminate knockingwhich would otherwise occur because of poor grades of fuel being used orbad conditions in the combustion chambers of the engine.

2. The method of controlling the advance and retardation of the sparkignitionin internal combustion engines, which comprises, retarding thetimes of ignition concurrently with the increased degrees of throttlevalve opening, and in addition thereto, manually increasing theretardations of the first mentioned times of ignition over apredetermined portion of the range of throttle valve openings, toeliminate knocking which would otherwise occur because of poor grades offuel being used or bad conditions in the combustion chambers of theengine.

LEO B. KIMIBALL.

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